beerwiz
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Distillation Setup for 1100°C (High Tmperature)?
I need to distill or more accurately sublime a compound that has a high boiling point of 1100°C. Regular glassware doesn't do it, I tried, the glass
melted completely in the furnace.
Any ideas or off the shelf products for doing such high temperature distillations/sublimations?
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Sulaiman
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Vacuum ?
CAUTION : Hobby Chemist, not Professional or even Amateur
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Heptylene
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A quartz tube?
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j_sum1
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I'd be building something out of steel at that temperature. Or maybe looking at ceramic.
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Tsjerk
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What is the compound? Or at least what kind of compound is it? That is probably quite relevant here.
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DraconicAcid
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Glassware starts to soften around 500, so 1100 is out of the question. Steel.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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Tsjerk
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There is a wide range of compounds that would eat any material, steal or not, for breakfast at 1100. There is a small range of compounds for which the
type of steal would make a difference.
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Fulmen
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Steel? That would be nice. But I don't think you'll find any alloy that beats 304SS, and it can't even handle 900°C. You could perhaps solve that by
coating it with ceramic textiles or similar, but your substance better not be reactive or soluble in near-molten steel.
We're not banging rocks together here. We know how to put a man back together.
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Tsjerk
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Quote: Originally posted by Fulmen  | | Steel? That would be nice. But I don't think you'll find any alloy that beats 304SS, and it can't even handle 900°C. You could perhaps solve that by
coating it with ceramic textiles or similar, but your substance better not be reactive or soluble in near-molten steel. |
https://www.bssa.org.uk/topics.php?article=107
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SWIM
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How about fused quartz like Heptylene said?
A tube, a crucible, a flask.
Vycor will also handle those temperatures for a while. (rated 900C continuous, 1200 for brief periods)
If you're sublimating a solid how about a quartz Dewar condenser in a quartz flask?
Quartz does devitrify with many compounds at such temperatures though.
Tell me what you're doing and I'll let you know if it's on the lists of potentially damaging materials that came with the last quartzware I bought.
I think I've got a list for Vycor too that came with a flask.
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rockyit98
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nickle plated stainless steel.
"A mind is a terrible thing to lose"-Meisner
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Twospoons
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Steel is going to be pretty soft at that temp. You're only 200C from melting.
How about SiC or graphite - crucibles can be bought OTC.
Helicopter: "helico" -> spiral, "pter" -> with wings
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beerwiz
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I tried an open top ceramic crucible but the compound sublimated on the sides and lid of the furnace. A quartz tube would be good since quartz has a
melting point of 1750C. But a straight tube won't do it, how can it catch the sublimate? The sublimate will just escape from the top end. I need to
catch the sublimate somehow. Steel won't work because this sulfide reacts with it, carbon is also no good.
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draculic acid69
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I'm curious as to what sulfide compound is worth this kind of trouble
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Heptylene
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From personal experience, sublimated compounds don't travel (as vapor) very far in a tube. I tried with iodine in a 25 mm ID glass tube heated to
about 200 °C and the iodine all condenses within 20 cm of the heated part. With a tube of smaller diameter this is even less of a problem.
EDIT: I should mention the experiment was done under vacuum (10 mbar).
[Edited on 1-2-2020 by Heptylene]
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mekanochemical
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depending what you want to sublime... stainless steel normally resist up to 700~800°C
pure quartz or even alumina could resist, and remember that some chemicals can have a corrosive behaviour at high temperatures
Hue Hue Hue
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Steam
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Depending on what it is you are trying to sublime, you will need to chose your refractories so that you do not get any reactions with the ceramic and
the compound you are trying to purify. If you need to use a metal for fabrication some kind of tantalum/molly alloy should get you into the proper
temp range. Also, what if you used some kind of pre-heated carrier gas such as argon to help with the mass transport problem.
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clearly_not_atara
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How do you plan to distill through graphite?
I think you need to consider Inconel etc.
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BromicAcid
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Steel is cheap and it's not going to melt at those temps, just give it a go - cross your fingers and hope for the best. (Maybe mumble a prayer to St.
Albert)
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unionised
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Much the same way people distill through glass I guess.
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Tsjerk
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I believe we should stop talking about distillation and start talking about sublimation, as these two processes require different techniques.
Running a vacuum sublimation above the melting temperature of borosilicate seems challenging to say the least. So I would go for a non vacuum
sublimation. This is doable at 1100, you just need a furnace with a controllable temperature and a vessel standing up to 1100. The right stainless
steel alloy can do that, you can use a vertical "condensor" as your product will be a solid anyway.
A more correct term for this condensor would be something like a "depositor".
You only need some pipes and caps with the right thread. If you design it in a way that the depositor can be seperated, you only need four standard
components. A cap at the bottom, a pipe that fits the cap and acts like the reaction vessel,a double female connector, and a depositor. Done
[Edited on 2-2-2020 by Tsjerk]
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unionised
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I'm not sure that SS will cope with 1100C
https://www.bssa.org.uk/cms/File/StainlessSteels_at_HighTemp...
I'm not sure if anyone actually makes things from pure chromium; the melting point's high, but the reactivity may be an issue.
Silica and alumina tubes are easy to get.
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BromicAcid
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Note: The OP has not commented on this thread since it was created. There is no mention of vacuum in his original post. We have no clue what is
being sublimed, could just be some random inorganic that has "sublimes" listed under the boiling point where vacuum could be applied to reduce the
temperature or it could be something where thing have been optimized to run under vacuum.
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